Progenitor cells have been harvested from multiple adult tissues, and transplanted for tissue regeneration. Despite its scientific validity, cell transplantation has associated economic and regulatory challenges in clinical translation including immune rejection, pathogen transmission, potential tumorigenesis, packaging/storage/shipping, and difficulties in clinical adoption and regulatory approval. Tissue regeneration by recruiting the host's endogenous cells, including progenitor cells, has been discussed in the art (see e.g., Agrawal et al. 2010 PNAS 107, 3351-3355). The ability of various cells, including MSCs, to migrate and home to various organs is well-established. (see e.g., Chamberlain et al., 2007, Stem Cells 25:2739-2749; Kan et al., 2005, Current Drug Targets 6:31-41; Loetscher and Moser, 2002, Arthritis Res. 4:233-236; Shi, M. et al., 2007, Haematologica 92:897-904; Sordi, V. et al., 2005, Blood 106:419-427; U.S. Patent Application Publication US 2003/0129750 A1; U.S. Patent Application Publication US 2004/0258669 A1; U.S. Patent Application Publication US 2006/0110374 A1; U.S. Patent Application Publication US 2008/0193426 A1; PCT Patent Publication WO 2008/094689 A2).
PDGF is a growth factor (i.e., a protein) that plays a role in embryonic development, cell proliferation, cell migration, and angiogenesis. Naturally occurring PDGF is a dimeric glycoprotein composed of two A (-AA) or two B (-BB) chains or a combination of the two (-AB).